In roller mills used industrially, there is generally driven the grinding table which drives the grinding rollers via the grinding bed. In this instance, it is generally necessary to arrange a gearing mechanism below the grinding table. In mills having large throughputs, it is necessary to take into account high investment costs, long procurement times and unsatisfactory availability with such gearing mechanisms.
Therefore, it has already been proposed to drive the grinding rollers in place of the grinding table. If a plurality of grinding rollers are provided, it is thereby possible to distribute the power for driving the roller mill over a corresponding plurality of drives. In that manner, it is possible to use drives which are smaller and therefore cheaper.
In DE 38 01 728 C2 and DE 36 02 932 A1, the complete drive with the motor and gearing mechanism is provided on the pivot lever which retains the grinding roller. Owing to the substantial weight of the drive, however, increased demands are placed on the bearing of the pivot lever in this construction type. The motor is further subjected to powerful vibrations owing to the grinding process.
DE 197 02 854 proposes a motor which is fixed in position as an alternative construction type. The drive power is transmitted to the gearing mechanism which is secured to the pivot lever via a cardan shaft. That cardan shaft has to ensure both angular compensation and longitudinal axial compensation. However, since very high torques have to be transmitted to the grinding roller, the drive train has to have such dimensions that it is relatively complex and expensive.
DE 295 563 further discloses an edge mill having a driven table and an edge runner which is retained by means of a pivot lever. The drive of the edge runner is brought about via a fixed motor and a gearing mechanism which pivots with the pivot lever, the pivoting gearing mechanism extending into the edge runner.